This is a randomized, multicenter, double-blind, active-controlled study designed to compare the effect of the angiotensin II receptor antagonist, irbesartan, with amlodipine on renal function and urine protein excretion in hypertensive subjects with Type II diabetes mellitus accompanied by proteinuria. We hypothesize that once-daily administration of irbesartan 75 mg for 4 weeks, titrated to 150 mg for an additional 4 weeks and further titrated to 300 mg for an additional 6 weeks to hypertensive subjects with Type II diabetes mellitus and proteinuria (24-hour urine protein excretion > 1000 mg) will be safe and well-tolerated, and will not adversely affect serum creatinine when compared to treatment with a calcium channel antagonist. We also hypothesize that once-daily administration of irbesartan 75 mg for 4 weeks, titrated to 150 mg for an additional 4 weeks, and further titrated to 300 mg for an additional 6 weeks, to hypertensive subjects with Type II diabetes mellitus and proteinuria will produce a reduction in urine protein and albumin excretion.